Tile now, or must I level a pretty flat floor with a *slight* apex?

[DIYish]

I am installing 6x24" (152mm x 610mm) wood look porcelain tile in an approx 200 sq. ft. (6096mm) room. Rectified tile, remarkably flatter than some 'long' LFT's I've seen.

I had someone install 5/8" (15.875mm) plywood over the slatted subfloor. He told me the floor was pretty flat using a 7' (2133mm) level, and OK for tiling, so I installed backerboard over that and taped the seams.

I was doing a final check with an 8' (101.6mm) level (just bought it) and discovered that the floor near the center has an apex. That is the floor has a very subtle 'tenting' (inverted 'V' shape) from the high axis to the walls on either side. The apex is not a bump I could grind down, the floor just has a nominal slope on either side of the high points, such that it's flat, but not level, dipping about 1/2" (12.7mm) over 8' (2133mm) to the wall.

The angle is so slight that when I lay the titles parallel to the axis, toward both walls the slope cannot be seen either at the grout lines or across the tiles.

I've thought about leveling the floor with Versabond LFT (a non-sag thinset mortar that can be laid up to 3/4" (19.05mm) thick, using a jig and screed). It would would be a hassle, but part of me thinks it's just not worth it, that I should just tile because it won't be seen. I was planning on using tile leveling clip system because I don't think it will be a problem even with the slopes.

I just wanted to get some other thoughts on this before making the leap.

 

[Qwerty]

If you can't grind it down then maybe work with clips and varying adhesive bed thickness to keep as flat as possible.

 

[LM]

Any pics?
Is this your own premises or is it a job for a customer? I ask this because who has to make the decision of what they'll 'live' with?
By he book for a customer you should Level it with fibre reinforced levelling compound.

 

[DIYish]

Any pics?
Is this your own premises or is it a job for a customer? I ask this because who has to make the decision of what they'll 'live' with?
By he book for a customer you should Level it with fibre reinforced levelling compound.

Family room in my own (more of a fixer-upper than I realized) home

No pics. I'd almost be embarrassed. But I suppose I can take one.

 

[Qwerty]

I've had the same issue before and been unable to level due to thresholds at adjoining rooms. Self levelling is indeed the most sensible, least time consuming option

 

[LM]

In that case if your the person to please then you should easily be able to accommodate the falls with clips in conjunction with great attention to adhesive bedding. Make sure that whilst clamping the planks you have solid adhesive coverage and it should be fine. You'll know the floor falls slightly in both directions because you've had to deal with it, I doubt if a lay man would see it.

 

[DIYish]

In that case if your the person to please then you should easily be able to accommodate the falls with clips in conjunction with great attention to adhesive bedding. Make sure that whilst clamping the planks you have solid adhesive coverage and it should be fine. You'll know the floor falls slightly in both directions because you've had to deal with it, I doubt if a lay man would see it.

Thank you!